Glad to hear you are enjoying the game.
The "out the blue" dialogue is, as with a lot of Sammy and Tuckers interaction, is Sammy winding Tucker up since he never says hello or has any small talk. So Sammy talks rubbish until Tucker asks how she is doing.
School has always been open on weekends. It's meant to be a safe space for the youth to hang out. Plus I don't want to lock you out of content just because it's the weekend.
More things to spend your money on, including rent is planned. Hopefully it will be in soon.